JP2001511666A - Surgical stent that is radially expandable and does not contract axially - Google Patents

Abstract

Abstract: A surgical stent (10) is configured to be radially expandable in a body lumen, such as an artery, away from a central axis (2). The stent (10) is formed from a continuous compression material (20) that describes the cylindrical profile of the stent (10). Each compression member (20) is formed with a continuous curve (30), and each curve includes at least one valley (32) and at least one peak (36). A gap (40) is provided between adjacent compression members (20). An axial element such as a tie bar (50) is provided across each gap (40). Each tie bar (50) is attached to the adjacent compression material (20) through the valley (32) so that when the stent (10) expands radially, the compression material (20) moves. To maintain its position without causing the stent (10) to maintain its axial length without contraction. Providing other alternative elements between adjacent circumferential elements can provide a variety of flexibility between adjacent compression members (20).

Description

DETAILED DESCRIPTION OF THE INVENTION [Title of Invention]            Surgical stent that is radially expandable and does not contract axially [Technical field]         The present invention is capable of being radially inflated by surgical insertion into a body lumen, such as an artery. Functional cylindrical stents, especially when expanded radially Radially expandable surgical stent with little or no directional contraction You. [Background Art]         Surgical stents are surgically inserted into a body lumen, such as an artery, It is well known to reinforce, maintain, restore, or enhance the function of the cavity is there. For example, in cardiovascular surgery, damaged or collapsed coronary arteries It is often desirable to place the stent where it is likely to be. This stent Once in place, it reinforces that portion of the artery to create normal blood flow within that artery. Let One form of stent that is particularly desirable for insertion into an artery or other body lumen One is to increase the radius from a first relatively small diameter to a second relatively large diameter. It is an expandable cylindrical stent. Such radially expandable stents are And placed in the artery and inserted into the artery. Until it reaches the body through the patient's arterial route. To the catheter Applies radial outward pressure on the stent to radially Balloon mechanism or other mechanism that expands to increase its diameter Is provided. Such expandable stents have sufficient rigidity after expansion. That is, after the catheter is removed, the inflated state is maintained.         As a radially expandable stent, it is the ideal machine for a variety of different environments. There are a variety of different configurations to provide functionality. For example, Lau U.S. Pat. No. 5,514,154; 5,421,955, and No . U.S. Pat. No. 5,242,399), Barracci, U.S. Pat. 5,531,7 41), U.S. Pat. 5,522,882), Giant U.S. Pat. 5,507,771, and No.5. 5,314,4 44), Termin U.S. Pat. 5,496,277), Lane rice The national patent (No. 5,494,029), Maeda U.S. Patent (No. 5,50 7,767), U.S. Pat. 5,443,477), Khos ravi US Patent (No. U.S. Pat. No. 5,441,515) to Jesssen. No. U.S. Patent No. 5,425,739) to Hickle. 5,139,4 80), Schatz U.S. Pat. 5,195,984), Forden Bacher, U.S. Pat. 5,549,662), Wiktor's US No. (No. No. 5,133,732), each of which is inserted into a body lumen. To include some form of radially expandable stent.         However, each of these prior art stents has various disadvantages. Therefore, it cannot be an ideal stent. For example, such an expandable stent Are not particularly flexible, so their central axis is almost straight before expansion. Maintain shape. This lack of flexibility allows the stent to move along the arterial path. Difficult to access, resulting in the stent being properly positioned within the patient's body. It will be difficult to do. Another problem that exists with each of these prior art stents Reduces the axial length of these stents when they expand radially. The point is that it shrinks. The aforementioned Lau patent in U.S. Pat. 5,514,154 ) Teaches a stent design that attempts to limit axial shrinkage, but Even in surgery, there is some axial contraction, especially at one end Is inevitable.         Where a surgeon attempts to place a stent in an artery or other body lumen In this case, the surgeon must place the stent exactly where it is going to be. And is important. A drawback common to conventional stents is the radial expansion. Before the stent can be accurately placed in the desired location, When the tent expands radially, its axial contraction causes the stent to position. Is shifted and cannot be finally arranged at a desired position. Such an arrangement The problem with mistakes is that even though most stents are It is caused by the fact that it cannot shrink easily after doing so.         In addition, even in the case of medical devices, a stent is inserted into a body lumen It is often difficult to determine the exact location of the stent when performing the procedure. this It is difficult to position the stent accurately as A problem arises in that it is difficult to accurately arrange at a desired position. Therefore, It is an object of the present invention to provide for little or no axial contraction when radially expanded. And easy placement by medical instruments when positioning the stent It is to provide a possible radially expandable stent. [Disclosure of the Invention]         The invention has almost its entire axial length when expanded radially Or a radially expandable stent that does not contract at all. This stainless steel Is made from a continuous compressed material that acts as a circumferential element that describes the cylindrical contour of this stent. It is formed. Each compressed material is an individual member perpendicular to the central axis of the cylindrical profile of the stent. It is arranged on a plane parallel to the plane of the adjacent compressed material. This stent is Can have a variety of different numbers of compression members that are connected together to form a stent. However A first end compression member and a second end forming both ends of the cylindrical profile of the stent At least two compression members including a compression member are provided. Generally, these two ends An intermediate compression member is provided between the compression members.         Each of these compacts is such that they outline the cylindrical contour of the stent. To show a wavy contour. Therefore, each compressed material alternates along its length It has a continuous curved portion having a trough and a peak. Each valley is adjacent to this compressed material Form the part furthest from the compressed material to be compressed Is formed in the portion closest to. The amplitude of each compressed material is the bottom of each trough and the top of each crest. This amplitude is determined by the distance between the In this case, it is changed so as to be generally reduced.         End compression is attached to adjacent intermediate compression by tie bars . Here, a tie bar is an axial element that connects two adjacent compression members to each other. Act. The tie bars may also connect adjacent intermediate compression members together. Each tie bar is provided at a first joint provided at one end of the tie bar and at the other end. The tie bar is attached to the compression member by the second joint. No. The first joint and the second joint are both arranged in the valley of the compressed material. Ie Tie bars are provided across the widest part of the gap between adjacent compressed materials Have been. However, all of the gaps have tie bars or other axial elements No need to provide. Instead, a separate intermediate circumferential element is separated from its valley. Can be attached to each other by links connecting to their intermediate elements You. Attach adjacent compresses to each other depending on the flexibility required for the stent The number of valleys provided with tie bars can be changed as appropriate. When high flexibility is desired Has a relatively large number of valleys left empty, with tie bars between adjacent compression members There are relatively few valleys. The corrugated contour of the compressed material has no flat surface and It may have a meandering shape that is curved over the entire length of the A series of straight sections formed by connecting valleys and straight peaks to each other by straight inflections. It may be continued.         To improve visibility when viewed through a variety of medical devices, The compression material forming the first and second ends of the tent is gold, silver, platinum, etc. It can be formed from a radiopaque material. This allows the patient's body lumen During or after insertion of the stent into the stent, the first and second ends of the stent , Clearly visible through the medical device. [Brief description of drawings]   FIG. 1 shows that a surgical stent according to a preferred embodiment of the invention It is a perspective view showing the state before expanding in the direction.   FIG. 2 is a perspective view showing a state after the stent of FIG. 1 is expanded in a radial direction. You.   FIG. 3 is a cylinder projection to illustrate details of the construction of the stent of FIG. FIG. 3 is a plan view showing a stent projected on a three-dimensional plane.   FIG. 4 shows details of the configuration of the stent after radial expansion of FIG. FIG. 2 is a plan view showing a stent projected on a two-dimensional plane by a cylindrical projection.   FIG. 5 shows a first modification of the stent shown in FIG. FIG. 4 is a plan view showing a state before expansion into a state.   FIG. 6 is a plan view showing a state after the stent of FIG. 5 has been radially expanded. You.   FIG. 7 shows a second modification of the stent shown in FIG. FIG. 4 is a plan view showing a state before expansion into a state.   FIG. 8 is a plan view showing a state after the stent of FIG. 7 is radially expanded. You.   FIG. 9 shows a third modified example of the stent shown in FIG. FIG. 4 is a plan view showing a state before expansion into a state.   FIG. 10 is a plan view showing a state after the stent of FIG. 9 is radially expanded. is there.   FIG. 11 shows a modification of the stent of FIG. 9 in which the end compression material is radiopaque. FIG. 3 is a plan view showing a state before a stent formed from a transient material is radially expanded. is there.   FIG. 12 is a plan view showing a state after the stent of FIG. 11 is radially expanded; It is.   FIG. 13 shows the stent of FIG. 11 and FIG. Observation through a medical device that clearly identifies radiopaque material parts The lumen is clearly outlined by radiopaque staining. And stent sections formed from radiolucent materials, they can be clearly identified. It is shown with wavy lines to express the absence. [Best Mode for Carrying Out the Invention]         In each drawing, the same part is indicated by the same number over a plurality of drawing numbers. . Reference numeral 10 designates a radially expandable, non-axially contracting surgical stent. (FIGS. 1 and 2). The stent 10 is connected to a series of Figure 3 shows a generally cylindrical profile formed by a continuous circumferential element. Compressed material 20 They are connected to each other by a number of axial elements, many of which are -50. The compression member 20 is substantially corrugated, and the stent 10 When radially expanded, the amplitude 22 of the compressed material 20 decreases and its diameter increases. It is formed so that.         Essentially, as shown in FIGS. 1 and 2, stent 10 can Has basic features. Compressed materials 20a, 20b, 20c, 20d, 20e, 20 Continuous circumferential elements such as f each describe a cylindrical profile of the stent 10. Is facing the right direction. Each compression member 20 is connected so that the compression member 20 has a corrugated shape. It has a continuous curved portion 30 (FIGS. 3 and 4). Each compression member 20 is adjacent compression Is separated from the adjacent compression member 20 by a gap 40 provided between the compression member 20 and the member 20. Are located. A continuous tie bar 50 extends between adjacent compressed members 20, Across the gap 40, the adjacent compression members 20 are connected to each other. this When the stent 10 expands radially along the arrow R, the tie bars 50 It acts as an axial element that maintains the axial position of the compression material 20. These tyvas -50 has sufficient flexibility and is located sufficiently away from other tie bars 50 Before the stent 10 expands radially. When moving along other body lumens, the entire stent 10 is made flexible, Its central axis 2 can be bent.         In particular, in FIGS. 1 to 4, the details of the surgical stent 10 are clearly shown. It is shown. Each compression member 20 is desirably an elongated strip made of a material such as metal. Is a strand and is constrained to lie substantially within the cylindrical profile of stent 10 . Each compression member 20 has a waveform having a constant amplitude 22 (FIG. 4) and a wavelength 24 (FIG. 4). , Forming a cylindrical profile of the stent 10. That is, each The compression member 20 has a curved portion 30, which is formed by alternately continuous valleys. It is composed of a part 32 and a mountain part 36. Between adjacent valleys 32 and peaks 36, An inflection point 34 is provided to clarify the transition between the valley 32 and the peak 36.         Whether a part of the curved portion 30 is the valley portion 32 or the peak portion 36 is mainly distant. This is a recent problem. Consistently, the valleys 32 are adjacent to the compressed material 20 is the part farthest from the opposing part, and the peaks 36 That is, it is the portion closest to the opposing portion of the adjacent compressed material 20. Each valley 32 and each The ridges 36 are not located at a particular point on each bend 30, but along one An area extending from the inflection point 34 to the next adjacent inflection point 34. One of the curved portions 30 Whether the portion is the valley portion 32 or the peak portion 36 is also an analysis target of each curved portion 30. It is determined according to the viewpoint. For example, a first end 60 and a second end The bending portion 30 at a position away from 70 has a first end 60 on one side of the bending portion 30. With the nearest ridge 36 and closest to the second end 70 on the opposite side of this bend 30 It has a valley 32.         Each inflection point 34 is in one direction (ie, clockwise) ) In the opposite direction (ie, counterclockwise). Each inflection The point 34 is desirably a single point that occurs at the center and at the center of each wavelength 24 of each compact 20. Is the point. However, the inflection points 34 are not just points, And a straight line region between each valley 32. Preferably, each compression member 20 is adjacent The valleys 32 of adjacent compression members 20 are aligned with the adjacent compression members 20 so that The compression members 20 are axially aligned with each other, and the ridges 36 of each compressed material 20 are axially aligned with each other.         The gap 40 is disposed between a pair of adjacent compression members 20. Accordingly The compressed material 20a adjacent to the first end 60 and the compressed material 20a adjacent to the second end 70 Only one gap 40 is adjacent to the end compression member 20 such as 20f. The gaps 40 exist on both sides of the inter-compression members 20b, 20c, 20d, and 20e. I do. Desirably, each gap 40 is located between adjacent compression members 20. A space that does not intersect with the compressed material 20 adjacent to 40 is formed. In addition, As such, a tie bar 50 is provided across the gap 40.         The width of each gap 40 is such that the position of the gap 40 is Adjacent to the valley 32 or adjacent to the peak 36 of the compressed portion 20 Will change accordingly. At the gap 40, adjacent to the peak 36 of the adjacent compressed material 20 A minimum width 42 of the gap 40 is formed at each position (FIG. 4). gap At 40, each location adjacent to the valley 32 of the adjacent compression member 20 has a gap A maximum width 44 of 40 is formed (FIG. 4). Therefore, each gap 40 is An alternate pattern of a small width 42 and a maximum width 44 is drawn, and the cylindrical shape of the stent 10 is formed. I draw an outline.         Each maximum width 44 also allows the gap 40 to move away from the center plane of the gap 40. Lateral slot 46 which is a portion that extends toward the adjacent compressed material 20 (FIG. 4). The slot 46 is formed by a curved portion of the adjacent compressed material 20. 30 and the radial expansion of the stent 10 (ie, as indicated by arrow R in FIG. 2). Contour before or after radial expansion along) have. Desirably, before expanding radially along arrow R (FIG. 2) , Each slot 46 (FIG. 4) reflects the bulbous contour of the curved portion 30 (Fig. 3). The slot 46 is narrow at first, and then widens from this state. At the time of peeling, the compressed material 20 adjacent to the gap 40 is separated from the center plane of the gap 40. It extends toward one valley 32 of one curved portion 30. Stent 10 is radial After inflation (FIG. 4), slot 46 loses its bulbous profile and a gap An outline is drawn in which the width gradually becomes narrower in a direction away from the center plane of 40.         By giving the curved portion 30 of the compressed material 20 such a bulbous contour, Thus, the width of the slot 46 can be increased from a narrow state, and the compressed material 30 is Radially inflated along. This causes the stent 10 to C (FIGS. 2 and 4) and can be extended in the circumferential direction, and its radial expansion You can maximize the tension. The bulbous contour of such a slot 46 also During the initial expansion of the stent 10 in the radial direction, the amplitude 22 (the fourth Figure) is kept unchanged. After expanding sufficiently in the radial direction and fully expanding in the circumferential direction, Thus, the amplitude 22 of the compression member 20 starts to decrease substantially.         Within each gap 40 there is at least one tie bar 50. It is arranged to cross 40. The tie bar 50 preferably has a first end It has an elongated structure with a second end remote from it. The first end is at the first joint 52 The second end is attached to the first adjacent compression member 20 and the second end Is attached to the adjacent compression member 20. The first joint 52 and the second joint 54 are Preferably, the compression on both sides adjacent to the gap 40 in which the tie bar 50 is provided It is arranged in each valley 32 of the material 20.         During radial expansion of the stent 10, the axis along arrow A (FIG. 2) It is important to prevent directional shrinkage, so that at least the first end 6 0 and the tie bar 5 connecting to the end compression members 20a, 20f adjacent to the second end 70 The leading end of 0 is attached to the valley 32 of the end compression members 20a and 20f. First Connecting to the intermediate compression member 20 which is arranged at a distance from the end 60 and the second end 70 The second end of the rivet 50 can be attached to either the valley 32 or the peak 36. You.         At least one tie bar 50 is provided across each gap 40 and By disposing the joints 52, 54 of the diver 50 in the valley 32, the gap 40 The length of the slot 46 in the inside can be maintained. Therefore, the stent 10 moves along the arrow R. When expanding radially, the amplitude 22 of the compressed material 20 adjacent to each gap 40 Until the position where the compression starts to decrease, the space between the compressed materials 20 adjacent to the gaps 40 contracts. And not. Instead, the minimum width 42 of the gap 40 is increased, so that the compressed material 20, especially the end compression members 20a, 20f maintain their position.         One of the most important points in forming the stent 10 is that the first end 60 Providing a tie bar 50 across the gap 40 adjacent to the second end 70; The tie bar 50 is connected to the end compression member 2 forming the first end 60 and the second end 70. This is a point of attachment in the valleys 32 of 0a and 20f. Also, the intermediate compressed material 20b, 2 0c, 20d, and 20e can be attached to either the valley 32 or the peak 36. Wear. However, it is attached between the intermediate compression members 20b, 20c, 20d, and 20e. 1 to 4 in which the tie bar 50 is attached only to the valley 32. As shown in the figure, even when the valleys 32 are not attached to more valleys 32 than the hills 36, At least an equal number of valleys 32 and peaks 36 should be attached.         When the cross-sectional area of the tie bar 50 is reduced, in many cases, the tie bar 5 It is empirically clear that the 0 bends somewhat. Therefore, the adjacent compressed material 20 The tie bar 50 is connected to the valley portion 32 of the compression member 20 rather than the tie bar 50 connected to the ridge portion 36. Increasing the number of tie bars 50 may compensate for the possibility of the tie bar 50 bending. It is profit.         Desirably, each gap 40 extends from the valley 32 of each adjacent compression member 20. A tie bar 50 is provided. In theory, with such a configuration, As the tent 10 expands radially along arrow R, it expands axially along arrow A. The tie bar 50 bends slightly when placed in a body lumen, thereby In practice, the stent 10 may be slightly shortened, but with the same axial There is a slight possibility of maintaining directional length and causing minimal contraction or expansion It's just For reference, Lau, U.S. Pat. 5,514,154) In so-called non-shrinkable stents, such as the expandable stent taught by Even shrinkage on the order of half the amplitude of the circumferential elements forming such a conventional stent Can occur. The contraction of a conventional stent as taught by Lau is Where the axial element is the peak of the circumferential element and the part connecting the circumferential elements Occurs at the end of the stent.         The material forming the compression material 20 and other elements of the stent 10 is preferably Stainless steel with a sufficiently small cross-sectional area, thereby forming the compact 20 Until the elastic limit of the material to be formed is exceeded, an arrow R (FIG. 2) A radial force, such as a force along, can be easily applied. Such radius When a directional force is applied, the material forming the compression member 20 may be artificially deformed. As a result, the compression member 20 expands in the radial direction and extends in the circumferential direction, and the amplitude decreases. Compressed material Such deformation of the material forming 20 is theoretically possible up to a circular shape However, further deformation causes insufficient tension of the compressed material 20.         However, in practice, expanding the stent 10 to the maximum possible However, the compression member 20 shows a wave shape whose amplitude is slightly reduced. As the wavelength of 0 expands by the same amount as the expansion amount in the circumferential length of each compression member 20, Expansion to a degree provides structural strength to the entire stent 10. Compressed material 2 0 exceeds the breaking strength of the material forming the compressed material 20 even if it undergoes artificial deformation. And not. The material therefore exhibits similar properties as far as strength is concerned, It provides the desired function of supporting a body lumen in tension.         In addition, stainless steel is 40,000-75,000 per square inch. Zero pound yield strength and 90,000-125,000 pounds per square inch With a breaking strength. Therefore, by providing the stent 10 with sufficient radial strength, The material forming the compressed material 20 is higher than its yield strength and equal to or less than its breaking strength. It is easy to give such strength. This means that the compressed material 20 expands in the radial direction. This is true in that the process does not actually "bend" and "stretch" You. Techniques for expanding various stents such as the stent 10 are well known in the art. You. One such technique is to fill the stent with air or other fluids. A functional inflatable balloon, which is elastically inflated to provide a radius to the stent. Techniques exist for applying directional forces. For more information on such expansion techniques, see Since it is expressed in the above-mentioned plurality of patent publications, its description is omitted.         A first modification of the surgical stent 10 according to the preferred embodiment, The surgical stent 110 (FIGS. 5 and 6) is a part of the stent 110. Has a link 180 that crosses the The configuration of this stent 110 is as follows: Similar to the preferred embodiment described above, except for the unique features described below. is there. That is, the stent 110 is compressed by a compression element which is a circumferential element of the stent 110. The compression member 120 includes the compression member 120 according to the above-described preferred embodiment. It has a curved portion 130 similar to the curved portion 30 of the material 20, and the adjacent compressed material 120. A gap 140 is provided between them. Each curved portion 130 has an alternately continuous valley. It comprises a part 132 and a peak part 134. The tie bar 150 is preferably used as described above. Similar to the tie bar 50 in the embodiment, It is inserted so that it crosses, and the link 180 is provided in the other gap 140. Have been. Desirably, a gap adjacent the first end 160 and the second end 170 The tie 140 is provided with a tie bar 150. And these tie bars 15 0 is desirably located between the valleys 132 of adjacent compression members 120. First The other gap 140 located away from the end 160 and the second end 170 of the , One of the tie bar 150 and the link 180 can be provided.         Each link 180 has a left end 182 (FIG. 6), a right end 184, and Has a bent portion 186 provided at the center between the left end 182 and the right end 184 It has an elongated structure. Therefore, the link 180 has the left end 182 Arm 187 extending from the right end 184 to the bending portion 186. There is provided a right arm 188 extending from the right arm. Preferably, the bend 186 is a left arm The arm 187 and the right arm 188 are perpendicular to each other. The bent portion 186 is connected to each link 180 The left arm 187 and the right arm 188 of each other flexibly approach and move away from each other in the direction of arrow F. In the arterial path. The flexibility of the stent 110 when it is inserted can be increased.         The link 180 desirably has a gap 14 where the link 180 is located. It is provided in the minimum width 142 portion within 0. Preferably, link 180 is located The gap 140 alternates with the gap 140 where the tie bar 150 is located. And includes a gap 140 adjacent the first end 160 and the second end 170. Absent. When the stent 110 is expanded in the radial direction, the vibration of the curved portion 130 of the compressed material 120 is caused. The width is reduced, and the link 180 forms the gap 136 of the adjacent compression member 120 by a gap. Hold across 140. This link 180 has a contraction effect on the stent 110. Easy to give. However, the tie bar inserted between the valleys 132 of the adjacent compression members 120 150 easily gives the stent 110 an expansion effect. Tie bar 150 expands in the axial direction Effect, and the net result of link 180 providing an axial contraction effect. When the stent 110 is radially expanded, there is no contraction of the stent 110. Alternatively, it is minimal.         Preferably, three ties are provided in the gap 140 where the tie bar 150 is provided. A bar 150 is provided, and the compression member 120 has a half for placement of the tie bar 150. Six valleys 132 and six peaks 136 are provided so that only one is used. Preferably, the gap 140 where the link 180 is provided has two links 180. Only. As a result, the four maximum widths 142 are left empty. Become. The location of link 180 desirably increases the flexibility of stent 110 further. In the circumferential direction with respect to the position of the tie bar 150.         FIGS. 7 and 8 show a second modification of the stent 10 as an individual. Shown is a stent having compression members and links formed from linear segments of ing. This stent 210 also has a circle formed by a plurality of compression members 220. Shows a cylindrical contour. Of the configuration of the stent 210, the above-described preferred embodiment Only the portions different from the configuration of the stent 10 according to the embodiment will be described below. Each of the compression members 220 has a wave-like appearance composed of a continuous curved portion 230. However, each curved portion 230 is provided with a flat valley portion 234 (FIG. 8). The valleys 234 are parallel to and axially spaced from the plurality of flat ridges 236. Are provided. Each of the flat valley 234 and the flat ridge 236 is desirable Are arranged in a plane orthogonal to the central axis of the stent 210 (see central axis 2 in FIG. 2). Is done.         Each flat valley 234 is connected to the flat ridge 236 adjacent by the inflection leg 235. It is connected. Each inflection leg 235 is desirably linear, and 4 and the flat ridge 236 are not parallel. The flat adjacent to the end of the inflection leg 235 A corner 237 is provided at the transition between the flat valley 234 and the flat ridge 236. You. The stent 210 is configured such that the compression member 220 has a rectangular shape with respect to its curved portion 230. Except for deforming into a shape, the stent 10 according to the preferred embodiment described above Similarly, it expands in the radial direction. Radial expansion as in the preferred embodiment described above At times, the amplitude 22 of the compression material 220 decreases and the wavelength of the compression material 220 increases.         A gap 240 is provided between adjacent compression members 220 of the stent 210. Have been. A gap 240 is formed between the flat valleys 234 of the adjacent compression members 220. A cutting tie bar 250 is provided. Such a tie bar 250 is desirable Is located in gap 240 adjacent first end 260 and second end 270. The other gap 240 of the stent 210 is selectively disposed.         Instead of the tie bar 250, the arched link 28 that crosses the gap 250 0 (FIG. 8) can also be provided. Preferably, each arched link 280 Has a left end 282 and a right end 284 remote therefrom. The space between the right ends 284 is bent in an arc shape. Preferably, arched link 280 Is between the adjacent flat ridges 236 of the compression member 220 adjacent to a certain gap 240 Inserted and traversing its gap 240. The arched link 280 is A function similar to that of the link 180 of the first modified example is provided. That is, this arch Link 280 connects adjacent gaps 240 to provide local shrinkage. This offsets the local expansion caused by the tie bar 250. as a result, If the stent 210 undergoes any contraction or expansion in the axial direction during radial expansion, However, it is insignificant for the entire stent 210.         As another example of the compression member 220, an arched link 280 is It is also possible to replace it. In the second modification, preferably, the gear A tie bar 250 is attached to each flat valley 234 facing the An arched link 280 is attached to each flat ridge 236 facing the step 240. Therefore, there is no empty space in both the flat valley portion 234 and the flat mountain portion 236. become. In such a configuration, the flexibility of the stent 210 is minimal. As radial strength is most important, flexibility is only of secondary importance Applicable when In addition, as another example, the above-described preferred embodiment and the first embodiment As in the modified example, it is possible to provide an empty space in the valley portion 234 or the peak portion 236.   9 and 10, the stent 10 according to the preferred embodiment is shown in FIG. The details of the third modification are shown. The stent 310 according to the third modification is , A multi-element joint 380. Details of this stent 310 The details are similar to the stent 210 except for the features described below. That is, The stent 310 has a continuous compression to describe the cylindrical profile of the stent 310. Materials 320 which are corrugated with curved portions 330 ing. A gap 340 is provided between adjacent compression members 320. one Adjacent to every other gap 340, and especially the first end 360 and the second end 370. A tie bar 350 is provided in the contacting gap 340. Other gap 3 40 is provided with a tie bar 350 or the width of the gap 340 is reduced. The compression member 320 adjacent to the gap 340 is reduced to It is attached to the joint 380.         Essentially, the multi-element joint 380 is an arched link according to the second variant. 280, which replaces the gap 3 with this multi-element joint 380. The width of 40 is reduced to zero. This stent 310 is similar to the stent 210 Inflatable. However, tie bar 250 aligns with multi-element joint 380 Therefore, each of the individual tie bars 250 is moved from the first end 360 to the second end Form a continuous axial element that extends to 380. Therefore, stent 3 The axial length of 10 is maintained with high precision without shrinkage. Axial shrinkage The only possibility is that rather than the placement of the elements that -350 caused by bending. Tie bar 350 is also limited to stent 310. Gives you flexibility. However, the stent 310 has a different configuration. It does not exhibit the same degree of flexibility as the stents 10, 110, 210 Really has only secondary importance, eliminating axial contraction and ensuring radial strength. It is suitable when maintaining is the most important.         FIGS. 11, 12, and 13 show details of the fourth modification. It is shown. This stent 410 is characterized only by its expansion range The details are clear from the details of the stent 310 according to the third modification. You. That is, the stent 410 has a cylindrical contour And a compression member 420 continuous with the compression member 420. The first end compression member 426 is connected to the first end 46. 0, the second end compression member 428 is adjacent to the second end 470. Placed. These end compression members 426, 428 are formed by the central compression member 420 and Formed from a unique material different from the material forming the other elements of the stent 410 . Thus, a material different from the material forming the other elements of the stent 410 may be used. The use of compression materials 426, 428 for other forms of stents 10, 110 , 210 and 310 are also possible.         The material forming the end compression members 426, 428 is desirably a medical device. Larger than the material forming the other parts of the stent 410 when viewed by It is a material that appears opaque until it stretches. For example, stainless steel End compression 426, 4 28 is gold, platinum, silver, their alloys, amalgam, or Can be formed from other similarly dense materials, and end compression using these materials The materials 426, 428 provide a clear image when viewed with a medical device.   That is, the end compression members 426 and 428 are plated with a radiopaque material. Not been. Rather, the end compression members 426, 428 are made of a radiopaque material. Therefore, it is constituted. This is important. Because the stent 410 The thickness of the elements that make up the stent can be reduced to This is because it increases by about an inch. Such plated stents are The operability is reduced, for example, it is difficult to guide through the pulse route. Also the end If the compact is thickened by plating, the radiopaque material may be relatively wide It has an external shape and is too bright when viewed with a medical device such as a fluoroscope. The radiopaque material of the stent It cannot be surely shown. The whole end compression material 426, 428 is radiopaque By using a material, defects due to plating can be avoided.         As shown in FIG. 13, the end compression members 426, 428 are "radiopaque". When formed from a material, the ends 460, 470 of the stent 410 may be It is clearly identifiable by the device. The lumen L in which the stent 410 is arranged Coats this lumen L with a radiopaque dye, as is well known in the art. Doing so emphasizes the medical device. And of the stent 410 Before or after inflation, the exact position of the stent 410 within this lumen L To determine, a medical device such as an X-ray is used. As shown by the broken line in FIG. In addition, other portions of the stent 410 are not visible when viewed with a medical device. It can only be perceived as vague or vague. Preferably, the end compression member 42 The radiopaque material forming 6, 428 is simply added to the end compression members 426, 428. Rather than being plated, the entire end compression 426, 428 was selected Formed from material.         With regard to use and operation, as shown in FIGS. 1, 2 and 13 Describes the details of the operation of the stents 10, 110, 210, 310, 410. I have. In an initial state, the stent 10 or a stent 110 of a modified example thereof, 210, 310, 410 are not radially expanded, as shown in FIG. The stent 10 is placed at a desired location using conventional techniques such as catheterization. You. The stent 10 is then expanded radially along arrow R (FIG. 2). As a result, the wavelength 24 increases, the amplitude 22 decreases, and the circumferential length increases. Increase (along arrow C in FIG. 2). In this case, the stent 10 is It is inflated to the desired expansion diameter in the treatment. The stent 10 is formed as described above. The first end 60 and the second end 7 have the configuration shown in the description and drawings. 0 maintains precise position relative to each other and body lumen throughout the inflation process I do. Therefore, there is almost no contraction or expansion in the axial direction of the stent 10. Does not occur at all.         When the stent 410 according to the fourth modification is used, 10 are arranged as in the preferred embodiment described above. However, the stent 41 Before expansion of the stent 410, a radiopaque dye is placed in the lumen in which the stent 410 is placed. Is implanted, and using a medical device such as an X-ray Confirmation is made that the position is correct. Stent 410 is in desired position If the stent 410 is not positioned correctly, before expanding the stent 410, Additional manipulation of the stent 410 is performed. Stent 410 placed at desired location Once the medical professional is convinced that this has been done, similar to the preferred embodiment described above, The tent 410 is inflated. Immediately afterwards, a doctor Use the medical device to verify that the stent 410 is maintaining the desired position. Follow-up surveys can be conducted.         In the present invention, the stent 10, 110, 210, 310 , 410, it is clear that the specific configuration of the elements can be changed as appropriate. You. For example, in each of the above-described embodiments, six consecutive compression members 20, 120, 220, 320, 420 are shown, but depending on the specific requirements of a particular operation, more It is also possible to provide a compression material or a smaller number of compression materials. In addition, each compressed material 2 0, 120, 220, 320, and 420 have six continuous curved portions 30, 130, respectively. , 230, 330 are provided, but if at least one curved portion is provided, Often, the number of bends can be larger or smaller. The above In addition to each form, various forms with different types and numbers of circumferential elements and axial elements can be implemented Noh. For example, a multi-element joint, such as joint 380, may be implemented in the preferred embodiment described above. In order to connect adjacent ridges 36 of the compression member 20 of the stent 10 according to the embodiment, It is also possible to use. Similarly, the stent according to the preferred embodiment described above. At 10, it is also possible to provide a tie bar 50 in all its slots 46. You. [Industrial applicability]         As described above, the present invention provides a method for radially inserting a body into a body lumen. The present invention provides a directionally expandable stent, wherein the stent is axially expanded during radial expansion. It has high industrial applicability in that it does not shrink in the opposite direction.   It is another object of the present invention, particularly when a stent is delivered into a patient's arterial tract. And to provide a stent whose central axis is flexible enough to bend.   Another object of the invention is to reduce or minimize shrinkage at its ends during radial expansion. It is to provide a surgical stent that does not occur at all.   Another object of the present invention is to provide a radiation source whose ends are easily visible by medical devices. It is to provide a surgical stent formed from an impermeable material.   Another object of the invention is to form a circumferential element that outlines the cylindrical contour of a stent. Formed from a continuous compressed material, the individual compressed materials are connected to each other by tie bars During radial expansion, this tie bar is used as an axial element to suppress contraction between compressed materials. The objective is to provide a surgical stent that functions as a surgical stent.   Another object of the present invention is to provide machining, photoetching or other precision processing. Provide surgical stents with configurations suitable for manufacturing by various technologies including cost technology Is to provide.   Another object of the present invention is to provide a body when inserted into a body lumen and expanded radially. Provided is a surgical stent configured to have sufficient strength to support a body lumen It is to be.   It is another object of the present invention to provide a surgeon with a high degree of accuracy within a body lumen. To provide a medical stent.   Other objects of the present invention will be apparent from the description of the specification and claims, and the accompanying drawings. Is.

────────────────────────────────────────────────── ─── Continuation of front page    (81) Designated countries EP (AT, BE, CH, DE, DK, ES, FI, FR, GB, GR, IE, IT, L U, MC, NL, PT, SE), OA (BF, BJ, CF) , CG, CI, CM, GA, GN, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, M W, SD, SZ, UG, ZW), EA (AM, AZ, BY) , KG, KZ, MD, RU, TJ, TM), AL, AM , AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, CU, CZ, DE, DK, EE, E S, FI, GB, GE, GH, GM, GW, HU, ID , IL, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, M G, MK, MN, MW, MX, NO, NZ, PL, PT , RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, US, UZ, V N, YU, ZW (72) Inventor Franzen John Jay.             United States of America, 95228 California               Copperlopolis Poker Flat             Road 424

Claims (1)

[Claims]         1. It has a generally cylindrical profile before and after radial expansion, allowing for surgical insertion into the body lumen For radially expandable and little axial contraction for insertion into And   At least three circumferential elements are provided, each circumferential element delineating the cylindrical contour. And a first circumferential element defines a first end of the stent. Forming a second circumferential element forming a second end of the stent;   Each said circumferential element is waved such that this element describes the cylindrical profile of the stent. It has a curved part with a continuous shape,   Each said curved portion has a valley and a crest, said valley being a circumferential element of another of said circumferential element. Forming a portion that is farther from the adjacent circumferential element than the Forming a portion closer to the adjacent circumferential element than other portions of the circumferential element,   At least one axial element having two ends has at least one pair of adjacent elements Disposed between circumferential elements, each end of the axial element being connected to the pair of adjacent circumferential Attached on different sides of the element to connect between the pair of circumferential elements,   Each said end of said axial element is adjacent to said circumferential element at one of said valleys Attached to one   Thereby, the axial element causes this stent to expand upon radial expansion of the stent. To prevent axial contraction of the A stent characterized by the following:         2. The axial element is formed linearly elongated between the ends thereof, Disposed parallel to the central axis of the cylindrical profile of the stent The stent according to claim 1, wherein:         3. The circumferential element is in an axial direction between one of the valleys and one of the peaks; Having an amplitude defined by distance, each said circumferential element being adjacent by a gap And the gap is formed such that the peaks of adjacent circumferential elements are separated from each other. And the maximum width at which the valleys of adjacent circumferential elements are furthest away from each other. Each said axial element has a length equal to the sum of said amplitude and said minimum width. One 3. The stent according to claim 2, wherein:         4. In all the circumferential elements, each valley facing an adjacent circumferential element Has an axial element located and attached to this valley The stent according to claim 1, wherein:         5. The stent includes at least one connecting element having two connecting ends. Wherein the connecting element is disposed between at least one pair of adjacent circumferential elements, and wherein each The connecting ends are respectively attached to different sides of the pair of adjacent circumferential elements. The pair of circumferential elements are connected to each other, and each of the connecting ends is connected to one of the valleys. Attached to the circumferential element The stent according to claim 1, wherein:         6. The connecting element comprises several adjacent circles forming the stent. Disposed in the gap between the peripheral elements, the axial elements forming the stent Located in the gap between several adjacent said circumferential elements, within each said gap The circumferential element adjacent to the gap where at least one element is arranged The connection elements are attached to each other, The axial elements are arranged every other gap and the axial elements are arranged every other gap The elements are provided in a pattern that The stent according to claim 5, characterized in that:         7. Within each said gap only the same elements are arranged, in which Each said gap, in which the axial element is arranged, has the connecting element arranged therein. Having a greater number of axial elements than the number of connecting elements in each said gap 7. The stent according to claim 6, wherein:         8. Each said connecting element is such that said connecting element crosses said gap. And arched to draw a curve extending between the peaks of adjacent circumferential elements. Has been formed The stent according to claim 7, characterized in that:         9. A first arm connected to each other by a bend And the second arm are bent, and the first arm is One of the ridges of the circumferential element on one side of the gap where the tying element is located The second arm is opposite the gap in which the connecting element is located Attached to one of the peaks of the circumferential element on the side, the connecting element being Means for bending around the bent portion so as to bend the central axis of the The stent according to claim 7, characterized in that:         10. Each of the peaks is positioned on each front so that each circumferential element has a constant amplitude. It is located at the same distance in the axial direction from the valley The stent according to claim 1, wherein:         11. Each of the valleys and each of the peaks are at least in the radial direction If not expanded, it is bulbous, whereby Within the gap between adjacent peaks, a lateral slot is provided on one side of the gap. The width between adjacent valleys of two circumferential elements on either side of this gap provided Is first decreasing, and then the transverse slot is moved from the center of the gap to the Grows as it expands toward the circumferential element The stent according to claim 10, wherein:         12. Each said circumferential element is perpendicular to the central axis of said cylindrical profile of said stent. An intersecting linear valley and the valley perpendicular to the central axis and by the amplitude of the circumferential element. Straight ridges axially separated from the ridges, and not parallel to the valleys and ridges And a continuous linear portion including an inflection portion connecting each valley portion to each adjacent peak portion, Is formed The stent according to claim 1, wherein:         13. Said first circumferential element forming said first end of said stent; Each of the second circumferential elements forming the second end of the stent may include an imaging device. When viewed by placement, is more opaque than the material forming the other parts of the stent. All of it is made of a material that has the means to make it clear The stent according to claim 1, wherein:         14． Radial expansion with cylindrical profile for insertion into body lumens In a possible surgical stent,   A plurality of circumferential elements are provided, each circumferential element defining the cylindrical profile of the stent. Around   At least two of the plurality of circumferential elements have at least one valley and at least one valley. A wavy shape including one crest, wherein the wavy circumferential element is the cylindrical shape of the stent; I draw a shape contour,   At least one axial element is arranged between two adjacent said circumferential elements, Axial element is attached to one of said adjacent circumferential elements at a first joint Attached to the other of said adjacent circumferential elements at a second joint,   The first joint is disposed at a distance from the peak, and the second joint is It is arranged at an interval from the peak A surgical stent, characterized in that:         15. The plurality of circumferential elements are located at the first end of the stent. A first end corrugated circumferential element disposed at the second end of the stent At least a second end corrugated circumferential element and at least one intermediate circumferential element. Also includes three circumferential elements,   The stent includes at least one first end axial element and at least one A first end including at least two axial elements including a second end axial element; A partial axial element is attached to one of the valleys in the first end corrugated circumferential element. Wherein said second end axial element is said valley in said second end wavy circumferential element. Attached to one of the parts 15. The stent according to claim 14, wherein:         16. Each said circumferential element has said wave shape The stent according to claim 15, characterized in that:         17． Each of the circumferential elements is attached to its valley via the first joint. Attached to the valley of the adjacent circumferential element via the second joint. At least one said axial element is provided 17. The stent according to claim 16, wherein:         18. Each said intermediate circumferential element opposes said first end corrugated circumferential element. A first side surface and a second side surface facing the second end corrugated circumferential element; The at least one valley of the first side and the second side has the axial element Are mounted, the axial element also having at least one adjacent Also attached to the valley of the circumferential element The stent according to claim 17, characterized in that:         19. Each said intermediate circumferential element opposes said first end corrugated circumferential element. A first side surface and a second side surface facing the second end corrugated circumferential element; At least one valley on one of the side faces is fitted with one of the axial elements And the axial element is also located in a valley of at least one adjacent said circumferential element. Is attached, and at least one peak of the other said side is provided with a connecting element Are attached, and the connecting element is also attached to the peak of the adjacent circumferential element. Attached The stent according to claim 17, characterized in that:         20. Characterized by a non-contracting end, having a cylindrical profile and a lumen A surgical stent radially expandable within   A first end circumferential element surrounding the cylindrical profile of the stent;   A second end circumferential element surrounding the cylindrical profile of the stent;   At least one intermediate circumferential element surrounding the cylindrical profile of the stent. Provided,   The first end circumferential element and the second end circumferential element have at least one valley. And a wave shape including at least one peak, and the wave-shaped circumferential element is Draws the cylindrical contour of the   One intermediate circumference element adjacent to the first end circumference element of the intermediate circumference element At least one first end axial element between the element and its first end circumferential element. A first end axial element, wherein the first end axial element is disposed in the first end circumferential element. Connected to one of the valleys and connected to said adjacent intermediate circumferential element;   One intermediate circumference element adjacent to the second end circumference element of the intermediate circumference element At least one second end axial element between the element and its second end circumferential element. A second end axial element is disposed in the second end circumferential element. Connected to one of the valleys and to the adjacent intermediate circumferential element. A surgical stent, characterized in that: